1. Field of the Invention
The present invention generally relates to a photographic camera and, more particularly, to a photographic camera equipped with an electric flash unit.
2. Description of the Prior Art
As is well known, in color photographs when a photo-taking is carried out with a flash unit fired direct towards a target object to be photographed, it often occurs that the resultant photo of the target object shows the presence of a red-eye phenomenon, the phenomenon in which the eyes of the target object photographically exposed on a film is colored in red. This red-eye phenomenon appears to have resulted from the situation in which flash light fired from a flash unit, after having entered into the eyeballs and subsequently reflected from the retinas, reaches a light sensitive film in a camera through the pupils of the target object.
In order to avoid the possible occurrence of the red-eye phenomenon, the prior art method such as disclosed in, for example, the Japanese Patent Publication No. 58-48088 published in 1983, is that the target object is preliminarily illuminated by a beam of light to cause the pupils to be closed prior to the actual photo-taking and the image of the target object is subsequently exposed on the light sensitive film.
However, it is well recognized that the possibility of occurrence of the red-eye phenomenon depends on various photo-taking conditions including, for example, the brightness of the surroundings of the target object, the camera-to-object distance, the distance from a photo-taking lens assembly of the camera and a flash firing window of the flash unit used, etc. Accordingly, where the beam of light is emitted for the purpose of avoiding the possible occurrence of the red-eye phenomenon according to the prior art method even in the case where the possibility of occurrence of the red-eye phenomenon is relatively small, the result would be a waste of the electric power.
Also, it is not easy for a photographer to take a countermeasure to avoid the possible occurrence of the red-eye phenomenon in anticipation of the possibility of occurrence of the red-eye phenomenon.